/**
 * 
 */
package com.hsxc.cdz.base.util;

import java.util.Random;
import java.util.UUID;

/**
 * @author wpfei
 *
 */
public class GetRandnum {
	public static String create_nonce_str() {

		// return UUID.randomUUID().toString();
		String noncetemp = UUID.randomUUID().toString();
		String nonce_str = "";
		char[] noncechar = noncetemp.toCharArray();
		for (int i = 0; i < noncechar.length; i++)
			if (noncechar[i] != '-')
				nonce_str += noncechar[i];
		return nonce_str.substring(0, 4);
	}
	public static String genRandomNum(int pwd_len){
		//35是因为数组是从0开始的，26个字母+10个数字
		final int maxNum = 36;
		int i; //生成的随机数
		int count = 0; //生成的密码的长度
		char[] str = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9' };
		StringBuffer pwd = new StringBuffer("");
		Random r = new Random();
		while(count < pwd_len){
		//生成随机数，取绝对值，防止生成负数，
		i = Math.abs(r.nextInt(maxNum)); //生成的数最大为36-1
		if (i >= 0 && i < str.length) {
		pwd.append(str[i]);
		count ++;
		}
		}
		return pwd.toString();

}
	public static void main(String[] args) {
		System.out.println(genRandomNum(4));
	}
}
